Flow Cytometry Core Shared Resource - Project Summary/Abstract The Flow Cytometry Core provides Salk investigators access to state-of-the-art flow cytometry instrumentation, high quality services (ensuring that all samples are manipulated and analyzed appropriately), and expert consultation concerning the design and implementation of flow-based experiments. The facility is equipped with two staff-operated fluorescence activated cell sorters (FACS) and three analytical instruments that are available for independent operation. Training and support for users with all levels of experience are available at the Core. The Core manages a site license for data analysis software, and provides users with two analysis workstations. Flow cytometry is a powerful single-cell technique that is widely employed at the Salk Institute, with Cancer Center members accounting for 95% of overall usage. Examples of flow applications used by Cancer Center members include: 1) characterizing cellular phenotypes (e.g., DNA content, levels and rates of cell cycle progression, levels of apoptosis), 2) using fluorescent proteins to label, identify, and FACS purify specific types of cancer cells from animal models, and 3) using fluorescent antibody labeling approaches to resolve multiple cell types (e.g., to determine which populations of cells, including immune cells, are present within the tumor microenvironment). This latter technique is applied to an extremely diverse array of experiments, which is limited only by antibody availability and detection real estate. The facility staff fosters a collaborative environment, striving to provide an easily accessible comprehensive resource to the Institute and dedicates efforts to identify emerging flow technologies or applications that will be useful for Core users. The specific aims of this Shared Resource are to facilitate research by: 1) offering instrumentation ? the Core maintains a suite of instruments designed to meet the broad range of current and anticipated needs of Institute scientists (based on research developments and trends), 2) providing expertise ? the highly experienced Core staff is readily accessible to Salk investigators for the collaborative development of assays and/or protocols, 3) providing critical services ? Core staff provides high-quality, live cell-sorting services that are tailored to meet the varying needs of Institute scientists, 4) providing education, training, and support ? Salk researchers at all levels of expertise can receive training in all aspects of flow cytometry, from experimental design to data analysis, and 5) identifying and evaluating new technologies ? the Core seeks to continuously ensure that state-of-the-art flow capabilities are offered, thereby maximizing user benefit.